DISEASE CHARACTERISTICS: Histologically confirmed metastatic breast cancer Bidimensionally measurable disease Lesion at least 2 cm in at least 1 diameter No failure with prior adjuvant antiestrogens within the first 12 months of treatment No progression of disease during therapy with prior aromatase inhibitors or selective estrogen receptor modulators (SERMs) (including SERMs for prevention of osteoporosis) No history of known central nervous system (CNS) metastases No bone metastases as only tumor manifestation Hormone receptor status: Estrogen receptor and/or progesterone receptor positive